Previous studies from our group and others that have examined associations of genome wide DNA methylation profiles with behavioral exposures have pointed to immune pathways, particularly cytokines. We have shown that maternal deprivation in rhesus macaques is associated with changes in DNA methylation in promoters regulating genes in the immune response pathways [68]. Specifically, transcription factors, cytokines and their receptors, such as NFkB2, IL-16 and IFNγR2 gene promoters, were identified to be differentially methylated in T cells. In humans, we have described association between early life socioeconomic position (SEP) and adult WBC DNA methylation signatures in chemokines (CCL3, CXCL9, CCR1, CCR10, CCR3, CCR6), interleukins (IL-2, IL-4, IL-8, IL1RN), cytokine receptors (IL10RB, IL6RB) and transcription factors regulating cytokine gene expression (NFATC1, NF-IL3, IkBβ) [60]. DNA methylation alterations in white blood cell DNA that were associated with PTSD, included genes involved in inflammation, such as CLEC9A, ANXA2, TLR8 [27]. Lastly, in subjects with a lifetime history of depression, IL-6 and CRP serum levels were found to be elevated, where IL-6 methylation in WBC DNA showed an inverse correlation with circulating IL-6 and CRP [69].
